With more than 80 000 patients in the United States on waiting lists for a kidney-and more than 100 000 patients beginning treatment for end-stage renal disease each year-transplant programs must evaluate potential recipients in a fair and efficient manner. To this end, certain "absolute exclusion criteria" have been proposed to screen out candidates who will not sufficiently benefit from transplant. Some programs use elevated body mass index as such an exclusion criterion, given that some studies have reported an association with increased risk of delayed graft function and acute rejection, longer hospitalization, and decreased overall graft survival. Upon further examination, however, elevated body mass index turns out to be a poor evaluative criterion for transplant candidates, as it is only variably associated with negative transplant outcomes. Moreover, use of a body mass index cutoff is potentially discriminatory and may mask underlying prejudice against persons of size.